This invention relates to an apparatus and a method for sealing an envelope.
A conventional envelope sealing apparatus known to the applicants for incorporation in an inserter for preparing one or more inserts, inserting them into an envelope and sealing the envelope to form a finished mailpiece, comprises a stop against which the bottom edge of the envelope is advanced so that the envelope buckles in a direction for partially closing the flap to the body of the envelope, the closing being completed by a sealing device located laterally of the transport path along which the envelope is advanced against the stop, the sealing device pressing the flap against the envelope body. However, the stop needs to be adjustable in position according to the size of the envelope which adds to technical complexity and cost. In addition, re-setting the stop position each time the envelope size changes is inconvenient and time-consuming for the operator.
It is an object of this invention to provide an envelope sealing apparatus and a method for sealing the envelope, which can be used for sealing envelopes of different sizes without re-setting the envelope sealing apparatus each time the sealing apparatus is to be used for envelopes of a new size.
According to one aspect of the invention, there is provided an apparatus for sealing envelopes, comprising: apparatus for sealing an envelope, having a body and a flap with a crease line therebetween, comprising:
(a) first transport means for advancing the envelope with the flap in an open position in a transport direction along a transport path, said transport means being arranged for applying drive to the envelope at a first location;
(b) means for determining the position of the crease line along the transport path;
(c) envelope buckling means operative in response to the crease line reaching a predetermined position, to engage the envelope from opposite sides at a second location, spaced from the first location, and cause the envelope to buckle in a direction laterally of the transport path, thereby partially closing the flap to the envelope body, and
(d) sealing means located adjacent the transport path for receiving the buckling envelope with its crease line leading, for completing the closing of the flap to the body of the envelope.
Since the envelope is engaged by the envelope buckling means from opposite sides, while the envelope is in contact with the first transport means at a first location, the envelope buckling means being at a second location, the envelope buckles towards the sealing means, when the envelope buckling means are operating in response to the crease line arriving at a predetermined position. Then, the buckled envelope contacts the sealing means, due to the operation of the first transport means and/or the envelope buckling means, with the crease line leading. Due to the operation of the envelope buckling means, in response to the crease line reaching the predetermined position and the buckling means engaging the envelope from opposite sides, and not from one end of the envelope, the apparatus according to the invention can be used for sealing envelopes of different sizes, without resetting the envelope sealing apparatus each time envelopes of a new size are used.
The engagement of the envelope buckling means from opposite sides can for example be conducted by a roller pair transporting the envelope in a direction generally opposite to the transport direction of the first transport means. Furthermore, the roller pair of the envelope buckling means can alternatively be driven significantly slower than the first transport means to cause the envelope to buckle. As a further alternative, the engagement of the envelope buckling means from opposite sides can be conducted by a clamp, which holds the envelope by engaging two opposing clamp parts to the envelope from opposite sides, while it is moved in the transport direction, so that the envelope buckles.
As already indicated, a preferred embodiment of the apparatus for sealing an envelope comprises envelope buckling means which are arranged to be in driving engagement with opposite faces of the envelope, so as to apply drive to the envelope in a direction generally opposite to the transport direction of the first transport means. Thus, the buckling of the envelope can be achieved in a simple manner and within a short period of time.
In a preferred arrangement, the sealing means are arranged to close the envelope by applying pressure to the flap and body of the envelope from opposite sides.
It is advantageous if the first transport means are formed by a first roller pair and the envelope buckling means are formed by a second roller pair, since thereby the envelope can be continuously transported in an effective manner. In a preferred arrangement, one roller of the envelope buckling means is a drive roller and the other is a driven roller, arranged to be brought into and out of driving contact with the envelope.
It is also advantageous if the driven roller of the second roller pair is carried by a moveable inducer, the driven roller being arranged to be brought into and out of driving contact with the envelope by movement of the inducer, so that the operation of the envelope buckling means is controlled in a simple way.
In a further preferred arrangement, the inducer is pivotably mounted on a rotation axis. It is advantageous if the inducer comprises a first guide portion at the free end of which a protrusion is located for urging the crease line of the envelope into the sealing means, since it is thereby ensured that the envelope is brought into contact with the sealing means. Further, the first guide portion provides a smooth transport of the envelopes, and the first guide portion can also act as a diverter for envelopes or sheets in cases where sealing per se is not required, when the driven roller is in driving contact with the envelope.
According to another preferred arrangement, the sealing means comprises a sealing roller pair whose nip is arranged to receive the partially closed envelope with its crease line leading. Desirably, a drive roller of the transport means and the drive roller of the envelope buckling means together form the sealing roller pair for sealing the envelope, so that sealing an envelope can be achieved by a minimum of structural elements.
According to another aspect of the invention, there is provided a method for sealing an envelope, having a body and a flap with a crease line therebetween, comprising:
(a) transporting the envelope with its flap in an open position in a first direction along a transport path by applying drive to the envelope at a first location;
(b) engaging the envelope from opposite sides at a second location spaced from the first location, when the crease line reaches a predetermined position thereby causing the envelope to buckle in a direction laterally of the transport path to partially close the flap to the envelope body;
(c) applying pressure to the buckling envelope with its crease line leading at a location adjacent to the transport path, to complete the closing of the flap to the body of the envelope.
By engaging the envelope from opposite sides at a second location, when the crease line reaches a predetermined position, the envelope buckles with its crease line leading so that pressure can be applied to close the flap to the body of the envelope. Due to engaging the envelope from opposite sides and not from one end of the envelope, the actual length of the envelope is unimportant for sealing the envelope with its crease line leading. Thus, envelopes of different sizes can be sealed without resetting the envelope sealing apparatus due to engaging the envelope from opposite sides in response to the crease line arriving at a predetermined position.
In a preferred embodiment step b) of the method of the invention comprises applying drive to the envelope in generally the opposite direction to the first direction.
It is further advantageous to induce the envelope to buckle in the lateral direction by applying a force on the envelope between said first and second locations. Preferably, the envelope is advanced along the transport path with its open flap trailing.
Desirably, the drive to the envelope at said first location is maintained while engaging the envelope from opposite sides at the second location. The apparatus can be used simply to close an envelope, rather than to close and seal it, hence according to another aspect of the present invention there is provided an apparatus for closing an envelope, having a body and a flap with a crease line therebetween, comprising (a) first transport means for advancing the envelope with the flap in an open position in a transport direction along a transport path, said transport means being arranged for applying drive to the envelope at a first location, (b) means for determining the position of the crease line along the transport path, (c) envelope buckling means operative in response to the crease line reaching a predetermined position, to engage the envelope from opposite sides at a second location, and cause the envelope to buckle in a direction laterally of the transport path, thereby partially closing the flap to the envelope body, and (d) closing means located adjacent the transport path for receiving the buckling envelope with its crease line leading, for completing the closing of the flap to the body of the envelope.